Mainstream clinical practice in endovascular treatment of intracranial aneurysms has changed little since the 1990's when vaso-oclusive coil use became widespread. Certainly, improved catheters and other auxiliary devices (e.g., stents) have helped make coiling procedures safer and/or more effective. However, the art in achieving adequate and appropriate aneurysm coil packing is best accomplished by the most highly skilled physicians.
Where practicable, aneurysm exclusion by cover-type devices (e.g., as described in U.S. patent application Ser. No. 12/397,123 (US Publication No. 2009/0319023) to the assignee hereof) may be preferred. Certain other groups are attempting to shift the paradigm away from intra-aneurysm coil packing to achieve embolization via deployment of an extra-aneurysm flow disruptor/diverter stent in the parent vessel. These densely braided devices and/or multiple braid devices layered upon one another are placed in the parent vessel across the neck of an aneurysm with the intent to alter hemodynamics so as to effect embolization.
US Patent Publications 2006/0271149 and 2006/0271153, assigned to Chestnut Medical Technologies, Inc., disclose delivery systems such braid-type stents. In one example system, a coil socket holds the distal end of the implant until this end is released during delivery catheter retraction with grippers holding the proximal end of the implant. These grippers are able to maintain contact with the proximal end of the implant through compression by the delivery catheter sleeve surrounding the grippers. Upon sleeve withdrawal, the grippers release the proximal end of the stent.
System miniaturization of the referenced system(s) is limited by the gripper configuration. Also, the lack of an active release mechanism for detachment from the distal socket presents issues of inadvertent deployment and/or non-optimal control.
Accordingly, there remains a need for each of more robust/reliable and/or more compact systems for advanced braid-type implant delivery. The present invention offers such systems with various advantages as presented herein and others as may be apparent to those with skill in the art.